Liquid crystal display and method of manufacturing the same

ABSTRACT

A liquid crystal display is provided that includes: a substrate; a thin film transistor disposed on the substrate; a protection layer disposed on the thin film transistor; a first electrode and a second electrode disposed on the protection layer; an alignment layer disposed on the second electrode; and a roof layer facing the second electrode, wherein a plurality of microcavities are formed between the second electrode and the roof layer, the microcavities include a liquid crystal material, and the alignment layer includes a photo-alignment material.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2013-0116467 filed in the Korean IntellectualProperty Office on Sep. 30, 2013, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Field

The present invention relates to a liquid crystal display and amanufacturing method thereof.

(b) Description of the Related Art

A liquid crystal display is one type of flat panel display device thatis widely used. A liquid crystal display includes two display panels onwhich field generating electrodes such as a pixel electrode and a commonelectrode are formed, and a liquid crystal layer interposedtherebetween.

The liquid crystal display generates an electric field in a liquidcrystal layer by applying voltages to the field generating electrodes.The applied electric field determines orientations of liquid crystalmolecules of the liquid crystal layer and controls polarization ofincident light, thereby displaying an image.

In one technique for making a liquid crystal display that has beendeveloped, instead of forming an upper panel and a separate lower panel,a cavity is formed on one panel as an entire pixel unit, and the liquidcrystal is filled into the cavity for realizing the display. In thistechnique, the display device is manufactured so that a sacrificiallayer made of an organic material and a supporting member formed thereonare formed, and then removed, and the liquid crystal is filled to theempty space formed by the removal of the sacrificial layer through aliquid crystal injection hole.

In such a technique, it is essentially impossible to perform a rubbingoperation on an inner part of the cavity filled with the liquid crystalsuch that an alignment layer is rubbed vertically to the substrate.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the disclosure andtherefore it may contain information that does not form the prior artthat is already known to a person of ordinary skill in the art.

SUMMARY

A liquid crystal display in which an alignment material is horizontallyaligned inside a cavity, and a manufacturing method thereof areprovided.

A liquid crystal display includes a substrate; a thin film transistordisposed on the substrate; a protection layer disposed on the thin filmtransistor; a first electrode and a second electrode disposed on theprotection layer; an alignment layer disposed on the second electrode;and a roof layer facing the second electrode, wherein a plurality ofmicrocavities are formed between the second electrode and the rooflayer, the microcavities including a liquid crystal material, and thealignment layer includes a photo-alignment material.

The photo-alignment material may be a photoisomer type material.

The photo-alignment material includes a cis type photoisomer.

The photo-alignment material may include azo benzene.

The photo-alignment material may be photo-reacted to UV light having awavelength equal to or less than 365 nanometers.

A lower insulating layer disposed between the microcavities and the rooflayer and an upper insulating layer disposed on the roof layer may befurther included.

A capping layer disposed on the roof layer may be further included.

A liquid crystal injection hole forming region may be disposed between aplurality of microcavities, and the capping layer may cover the liquidcrystal injection hole forming region.

An interlayer insulating layer may be disposed between the firstelectrode and the second electrode, the first electrode may have aplanar shape, and the second electrode may include a plurality of branchelectrodes.

A plurality of branch electrodes may overlap the first electrode of theplanar shape.

A manufacturing method of a liquid crystal display includes: forming athin film transistor on a substrate; forming a protection layer on thethin film transistor; forming a first electrode and a second electrodeon the protection layer; forming a sacrificial layer on the secondelectrode; forming a roof layer on the sacrificial layer; removing thesacrificial layer to form a plurality of microcavities including aliquid crystal injection hole; injecting a photo-alignment material inthe microcavities; irradiating a polarized light to the photo-alignmentmaterial; baking the photo-alignment material; and injecting a liquidcrystal material into the microcavities.

The photo-alignment material may include a photoisomer type material.

The photo-alignment material may form a cis type photoisomer uponirradiation of the polarized light.

The photo-alignment material may include azo benzene.

The polarized light may have a wavelength equal to or less than 365nanometers.

The polarized light may have energy of about 4 J to about 6 J.

The method may include forming a lower insulating layer disposed betweenthe microcavity and the roof layer, forming an upper insulating layer onthe roof layer, and forming a capping layer on the upper insulatinglayer.

A liquid crystal injection hole forming region may be disposed betweenthe plurality of microcavities, and the capping layer may be formed tocover the liquid crystal injection hole forming region.

An interlayer insulating layer may be disposed between the firstelectrode and the second electrode, the first electrode may have aplanar shape, and the second electrode may include a plurality of branchelectrodes.

The branch electrodes may overlap the first electrode of the planarshape.

According to example embodiments, the photoisomer type material of ahorizontal alignment layer is used to form the alignment layer in thecavity. Accordingly, a wide viewing angle liquid crystal mode using thehorizontal alignment may be applied to the technique for realizing thedisplay by filling the liquid crystal in the cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a liquid crystal display according to anexample embodiment.

FIG. 2 is a cross-sectional view taken along a cutting line II-II ofFIG. 1.

FIG. 3 is a cross-sectional view taken along a cutting line of FIG. 1.

FIG. 4 to FIG. 14 are cross-sectional views showing a manufacturingmethod of a liquid crystal display according to an example embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure will be described more fully hereinafter withreference to the accompanying drawings, in which example embodiments areshown. As those skilled in the art would realize, the describedembodiments may be modified in various different ways, all withoutdeparting from the spirit or scope of the present invention. On thecontrary, example embodiments introduced herein are provided to makedisclosed contents thorough and complete and sufficiently transfer thespirit of the present disclosure to those skilled in the art.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. It will be understood that when a layer isreferred to as being “on” another layer or substrate, it can be directlyon the other layer or substrate, or intervening layers may also bepresent. Like reference numerals designate like elements throughout.

FIG. 1 is a top plan view of a liquid crystal display according to anexample embodiment. FIG. 2 is a cross-sectional view taken along acutting line II-II of FIG. 1. FIG. 3 is a cross-sectional view takenalong a cutting line of FIG. 1.

Referring to FIG. 1 to FIG. 3, a gate line 121 is formed on a substrate110 made of transparent glass or plastic. The gate line 121 includes agate electrode 124 and a wide end portion (not illustrated) for aconnection with another layer or an external driving circuit. The gateline 121 may, for example, be formed of an aluminum-based metal such asaluminum (Al) or an aluminum alloy, a silver-based metal such as silver(Ag) or a silver alloy, a copper-based metal such as copper (Cu) or acopper alloy, a molybdenum-based metal such as molybdenum (Mo) or amolybdenum alloy, chromium (Cr), tantalum (Ta), and titanium (Ti).However, the gate line 121 may also have a multiple layer structureincluding at least two conductive layers having different physicalproperties.

A gate insulating layer 140 formed of silicon nitride (SiNx) or siliconoxide (SiOx) is formed on the gate line 121. The gate insulating layer140 may also have a multiple layer structure including at least twoinsulating layers having different physical properties. A semiconductorlayer 151 disposed under a data line 171 and a semiconductor layer 154disposed under a source/drain electrode and corresponding to a channelportion of a thin film transistor Q are formed on the gate insulatinglayer 140. The semiconductor layer 154 may, for example, be made ofamorphous silicon or polysilicon, or an oxide semiconductor.

A plurality of ohmic contacts may be formed on each of the semiconductorlayers 151 and 154, and between the data line 171 and the source/drainelectrode, but they are omitted in the drawings.

Data conductors 171, 173, and 175 including a source electrode 173, thedata line 171 connected with the source electrode 173, and a drainelectrode 175 are formed on each of the semiconductor layers 151 and 154and the gate insulating layer 140. The data line 171 includes a wide endportion (not illustrated) for connection with another layer or anexternal driving circuit. The data line 171 transfers a data signal andextends mainly in a vertical direction to cross the gate line 121.

The source electrode 173 is a part of the data line 171, and is disposedon the same line as the data line 171. The drain electrode 175 is formedto extend in parallel with the source electrode 173. Accordingly, thedrain electrode 175 is parallel with the part of the data line 171. Thestructure of the source electrode 173 and the drain electrode 175 may bechanged.

The gate electrode 124, the source electrode 173, and the drainelectrode 175 form one thin film transistor Q together with thesemiconductor 154, and a channel of the thin film transistor is disposedin the semiconductor 154 between the source electrode 173 and the drainelectrode 175.

The data line 171 and the drain electrode 175 may, for example, be madeof refractory metal such as molybdenum, chromium, tantalum, and titaniumor an alloy thereof, and may have a multiple layered structure includinga refractory metal layer (not illustrated) and a low resistiveconductive layer (not illustrated). An example of the multilayeredstructure may include a double layer including a chromium or molybdenum(alloy) lower layer and an aluminum (alloy) upper layer, and a triplelayer including a molybdenum (alloy) lower layer, an aluminum (alloy)intermediate layer, and a molybdenum (alloy) upper layer.

A first protection layer 180 a is formed on the data conductors 171,173, and 175 and the exposed semiconductor layer 154. The firstprotection layer 180 a may include the inorganic insulator such assilicon nitride (SiNx) silicon oxide (SiOx), or an organic insulator.

A color filter 230 and a light blocking member 220 are formed on thefirst protection layer 180 a.

First, the light blocking member 220 has a lattice structure having anopening corresponding to a region displaying an image, and is formed ofa material preventing light from being transmitted. The color filter 230is formed at the opening of the light blocking member 220. The lightblocking member 220 includes a horizontal light blocking member 220 aformed in a direction parallel to the gate line 121 and a vertical lightblocking member 220 b formed in a direction parallel to the data line171.

The color filter 230 may display one of the primary colors, such as thethree primary colors including red, green, and blue. However, the colorsare not limited to the three primary colors including red, green, andblue, and the color filter 230 may also display one among a cyan-basedcolor, a magenta-based color, a yellow-based color, and a white-basedcolor. The color filter 230 may be formed of materials displayingdifferent colors for each adjacent pixel.

A second protection layer 180 b covering the color filter 230 and thelight blocking member 220 is formed on the color filter 230 and thelight blocking member 220. The second protection layer 180 b may includethe inorganic insulating material, such as silicon nitride (SiNx) andsilicon oxide (SiOx), or the organic insulating material. Contrary tothe illustration in the cross-sectional view of FIG. 2, in a case wherea step is generated due to a difference in a thickness between the colorfilter 230 and the light blocking member 220, the second protectionlayer 180 b includes an organic insulating material, so that it ispossible to decrease or remove the step.

The color filter 230, the light blocking member 220, and the protectionlayers 180 a and 180 b have a contact hole 185 exposing the drainelectrode 175.

A common electrode 270 is formed on the second protection layer 180 b.The common electrode 270 has a planar shape, may be formed on the entirefirst substrate 110 as a plate, and may have an opening 138 formed inthe region corresponding to the periphery of the drain electrode 175.That is, the common electrode 270 may have the planar shape of a plateshape.

The common electrodes 270 disposed on adjacent pixels are connected toeach other to receive a common voltage of a predetermined level suppliedfrom outside of the display area.

An interlayer insulating layer 180 c is formed on the common electrode270. The interlayer insulating layer 180 c may be formed of an organicinsulating material or an inorganic insulating material.

A pixel electrode 191 is disposed on the interlayer insulating layer 180c. The pixel electrode 191 may be formed of a transparent conductivematerial such as ITO or IZO. The pixel electrode 191 includes aplurality of cutouts 91 and a plurality of branch electrodes 192disposed between the adjacent cutouts.

The first protection layer 180 a, the second protection layer 180 b, andthe interlayer insulating layer 180 c have a contact hole 185 exposingthe drain electrode 175. The pixel electrode 191 is physically andelectrically connected to the drain electrode 175 through the firstcontact hole 185 to receive a voltage from the drain electrode 175.

The common electrode 270 is a first field generating electrode or afirst electrode, and the pixel electrode 191 is a second fieldgenerating electrode or a second electrode. The pixel electrode 191 andthe common electrode 270 may form a horizontal electric field, forexample, upon application of voltages to the electrodes. The pixelelectrode 191 and the common electrode 270 as field generatingelectrodes generate an electrical field such that the liquid crystalmolecules 310 disposed thereon are rotated in a direction parallel tothe direction of the electric field. As described above, according tothe determined rotation direction of the liquid crystal molecules, thepolarization of light passing through the liquid crystal layer ischanged.

According to the liquid crystal display of the shown example embodiment,the common electrode 270 has the planar shape and the pixel electrode191 has a plurality of branch electrodes, however in a liquid crystaldisplay according to another example embodiment, the pixel electrode 191may have a planar shape and the common electrode 270 may have aplurality of branch electrodes.

The present disclosure may be applied to all cases (i.e., any liquidcrystal display panel design) in which two field generating electrodesoverlap via an insulating layer on the substrate 110, the first fieldgenerating electrode under the insulating layer has a plane shape, andthe second field generating electrode on the insulating layer has aplurality of branch electrodes.

A lower alignment layer 11 is formed on the pixel electrode 191 and thelower alignment layer 11 includes a photo-alignment material. The loweralignment layer 11 may be a photoisomer type among the various types ofphoto-alignment materials, that is, the alignment material used to formthe lower alignment layer may include a photo-isomer material thatchanges between isomers upon irradiation with light. The photo-alignmentmaterial of the photoisomer type includes a trans type and a cis typephotoisomer, i.e., the photo-alignment material has a trans-type isomerstructure and a cis-type isomer structure, and the isomeric structurecan be changed upon irradiation with light. In the present exampleembodiment, the photo-alignment material of the alignment layer includesa cis type photoisomer.

In the case of the cis type photo-alignment material, a side chain ofthe photo-alignment material is arranged so as to be parallel to thesubstrate 110, thereby realizing horizontal alignment in which theliquid crystal is also arranged parallel to the substrate 110.

The photo-alignment material according to the present example embodimentmay, for example, include a cis type azo benzene as in Chemical Formula1.

An upper alignment layer 21 is disposed in a position corresponding tothe position over the lower alignment layer 11, and a microcavity 305 isformed between the lower alignment layer 11 and the upper alignmentlayer 21. The microcavity 305 is injected with a liquid crystal materialincluding liquid crystal molecules 310, and the microcavity 305 has aliquid crystal injection hole 307.

The microcavity 305 may be formed according to a column direction of thepixel electrode 191, in other words, the vertical direction. In thepresent example embodiment, an alignment material forming the alignmentlayers 11 and 21 and the liquid crystal material including the liquidcrystal molecules 310 may be injected into the microcavity 305 by usingcapillary force.

The microcavity 305 is divided in a vertical direction by a plurality ofliquid crystal injection hole forming regions 307FP disposed at aportion overlapping the gate line 121, and there may be multiple suchregions along the direction in which the gate line 121 is extended. Eachof the plurality of formed microcavities 305 may correspond to a pixelarea, and the pixel area may correspond to a region displaying an image.

A lower insulating layer 350 is disposed on the upper alignment layer21. The lower insulating layer 350 may be formed of silicon nitride(SiNx) or silicon oxide (SiO2).

A roof layer 360 is disposed on the lower insulating layer 350. The rooflayer 360 has a function of supporting the microcavity 305 to form themicrocavity 305. The roof layer 360 may, for example, include aphotoresist or other organic materials.

An upper insulating layer 370 is disposed on the roof layer 360. Theupper insulating layer 370 may contact the upper surface of the rooflayer 360. The upper insulating layer 370 may be formed of siliconnitride (SiNx) or silicon oxide (SiO2).

In the present example embodiment, the capping layer 390 covers theliquid crystal injection hole 307 of the microcavity 305 exposed by theliquid crystal injection hole forming region 307FP while filling theliquid crystal injection hole forming region 307FP. The capping layer390 includes an organic material or an inorganic material.

In the present example embodiment, as illustrated in FIG. 3, a partitionwall forming portion PWP is formed between the microcavities 305 whichare adjacent in a horizontal direction. The partition wall formingportion PWP may be formed in a direction in which the data line 171 isextended, and may be covered by the roof layer 360. The partition wallforming portion PWP is filled with the lower insulating layer 350, thecommon electrode 270, the upper insulating layer 370, and the roof layer360, and the structure forms a partition wall so that the microcavity305 may be divided or defined. In the present example embodiment, in thepartition structure, such as the partition forming portion PWP is formedbetween the microcavities 305 little stress is generated even though theinsulating substrate 110 is bent, and a degree in which a cell gap ischanged may be considerably decreased.

FIG. 4 to FIG. 14 are cross-sectional views of a manufacturing method ofa liquid crystal display according to an example embodiment.

An example embodiment for manufacturing the liquid crystal display willbe described referring to FIG. 4 to FIG. 14. The following exampleembodiment may be modified into other methods as an example embodimentof manufacturing method.

FIGS. 4, 6, 8, 10, 11, and 13 sequentially show the cross-sectionalviews taken along the line II-II of FIG. 1. FIG. 5, 7, 9, 12, 14sequentially show the cross-sectional views taken along the line of FIG.1.

Referring to FIGS. 1, 4, and 5, in order to form a generally knownswitching element on a substrate 110, the gate line 121 extended in thehorizontal direction is formed, and the gate insulating layer 140 isformed on the gate line 121, the semiconductor layers 151 and 154 areformed on the gate insulating layer 140, and the source electrode 173and the drain electrode 175 are formed. In this case, the data line 171connected with the source electrode 173 may be formed to be extended inthe vertical direction while crossing the gate line 121.

A first protection layer 180 a is formed on the data conductors 171,173, and 175 including the source electrode 173, the drain electrode175, and the data line 171, and the exposed portion of the semiconductorlayer 154.

The color filter 230 is formed at a position corresponding to the pixelarea on the first interlayer insulating layer 180 a, and the lightblocking member 220 is formed between the color filters 230.

The second protection layer 180 b that covers the color filter 230 andthe light blocking member 220 is formed on the color filter 230 and thelight blocking member 220, and the second protection layer 180 b isformed to have the contact hole 185 electrically and physicallyconnecting the pixel electrode 191 and the drain electrode 175.

The common electrode 270 having a planar shape is formed on the secondprotection layer 180 b. The common electrode 270 has the opening 138disposed at the portion overlapping the gate line 121 or the data line171, but may be formed to be connected in the adjacent pixels. Theinterlayer insulating layer 180 c is formed on the common electrode 270,and pixel electrode 191 is formed on the interlayer insulating layer 180c. The interlayer insulating layer 180 c has the contact hole 185physically and electrically connecting the pixel electrode 191 and thedrain electrode 175 along with the first protection layer 180 a and thesecond protection layer 180 b.

The pixel electrode 191 includes a plurality of cutouts 91 and aplurality of branch electrodes 192 disposed between the adjacent cutouts91.

The sacrificial layer 300 is formed on the pixel electrode 191. As shownin FIG. 5, the sacrificial layer 300 includes an open portion OPN formedaccording to the direction parallel to the data line 171. In the openportion OPN, the lower insulating layer 350, the roof layer 360, and theupper insulating layer 370 are formed thereby forming the partition wallforming portion (PWP).

Referring to FIG. 6 and FIG. 7, the lower insulating layer 350 and theroof layer 360 are sequentially formed on the sacrificial layer 300. Theroof layer 360 may be removed in the region corresponding to theblocking member 220 disposed between the pixel areas adjacent in thevertical direction by an exposure and development process. The rooflayer 360 exposes the lower insulating layer 350 in the regioncorresponding to the light blocking member 220. At this time, the lowerinsulating layer 350 and the roof layer 360 fill the open portion OPN ofthe longitudinal light blocking member 220 b, thereby forming thepartition forming portion (PWP).

Referring to FIG. 8 and FIG. 9, the upper insulating layer 370 coveringthe roof layer 360 and the exposed lower insulating layer 350 is formed.

Referring to FIG. 10, the upper insulating layer 370 and the lowerinsulating layer 350 are dry-etched to partially remove the upperinsulating layer 370 and the lower insulating layer 350, thereby formingthe liquid crystal injection hole forming region 307FP. At this time,the upper insulating layer 370 may have a structure that covers the sideof the roof layer 360, however it is not limited thereto, and theportion of upper insulating layer 370 covering the side of the rooflayer 360 may be removed thereby exposing the side of the roof layer360.

Referring to FIGS. 11 to 12, the sacrificial layer 300 is removedthrough the chemical liquid injection hole SE by an O₂ ashing process ora wet etching method. In this case, the microcavity 305 having theliquid crystal injection hole 307 is formed. The microcavity 305 is in astate of an empty space according to the removal of the sacrificiallayer 300.

Referring to FIG. 13 and FIG. 14, the photo-alignment material isinjected through the liquid crystal injection hole 307. Thephoto-alignment material injected into the microcavity 305 may includethe cis/trans type photoisomer as described above.

Next, polarized ultraviolet rays (UV) are irradiated to thephoto-alignment material injected in the microcavity 305.

In detail, the [cis type] azo benzene represented by Chemical Formula 1may be included in the photo-alignment material injected into themicrocavity.

Accordingly, the same effect as the rubbing may be obtained. Thepolarized ultraviolet rays may have a 365 nanometer wavelength, howeverit is not limited thereto, and a wavelength at equal to or less than 365nanometers may be used. Irradiation energy of the polarized ultravioletrays may be in a range of about 4 J to about 6 J. Upon irradiation withUV, the photo-isomer material is in one of the isomeric states, forinstance, it is in the cis-type isomeric states. In particular, if azobenzene is used as the photo-isomer material, upon irradiation with UV,cis-azo benzene is formed.

The photo-alignment material is then baked to form photo-alignmentlayers 11 and 21 on the inner walls of the microcavity 305.

A liquid crystal material including the liquid crystal molecules 310 isinjected into the microcavity 305 through the liquid crystal injectionhole 307 by using an inkjet method and the like. The liquid crystalmolecule 310 may be horizontally aligned.

The capping layer 390 is formed on the upper insulating layer 370 tocover the liquid crystal injection hole 307 and the liquid crystalinjection hole forming region 307FP thereby forming the liquid crystaldisplay as shown in FIG. 2.

While this disclosure has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the disclosure, including the appended claims.

<Description of Symbols> 300 sacrificial layer 305 microcavity 307liquid crystal injection hole 350 lower insulating layer 360 roof layer370 upper insulating layer 390 capping layer

What is claimed is:
 1. A liquid crystal display comprising: a substrate;a thin film transistor disposed on the substrate; a protection layerdisposed on the thin film transistor; a first electrode and a secondelectrode disposed on the protection layer; an alignment layer disposedon the second electrode; and a roof layer facing the second electrode,wherein a plurality of microcavities are formed between the secondelectrode and the roof layer, the microcavities include a liquid crystalmaterial, and the alignment layer includes a photo-alignment material.2. The liquid crystal display of claim 1, wherein the photo-alignmentmaterial is a photoisomer type material.
 3. The liquid crystal displayof claim 2, wherein the photo-alignment material includes a cis typephotoisomer.
 4. The liquid crystal display of claim 3, wherein thephoto-alignment material includes azo benzene.
 5. The liquid crystaldisplay of claim 4, wherein the photo-alignment material isphoto-reacted to UV light having a wavelength equal to or less than 365nanometers.
 6. The liquid crystal display of claim 2, furthercomprising: a lower insulating layer disposed between the microcavitiesand the roof layer; and an upper insulating layer disposed on the rooflayer.
 7. The liquid crystal display of claim 6, further comprising acapping layer disposed on the roof layer.
 8. The liquid crystal displayof claim 7, wherein a liquid crystal injection hole forming region isdisposed between the microcavities, and the capping layer covers theliquid crystal injection hole forming region.
 9. The liquid crystaldisplay of claim 8, wherein: an interlayer insulating layer is disposedbetween the first electrode and the second electrode, the firstelectrode has a planar shape, and the second electrode includes aplurality of branch electrodes.
 10. The liquid crystal display of claim9, wherein the branch electrodes overlap the first electrode of theplanar shape.
 11. A method manufacturing a liquid crystal displaycomprising: forming a thin film transistor on a substrate; forming aprotection layer on the thin film transistor; forming a first electrodeand a second electrode on the protection layer; forming a sacrificiallayer on the second electrode; forming a roof layer on the sacrificiallayer; removing the sacrificial layer to form a plurality ofmicrocavities including a liquid crystal injection hole; injecting aphoto-alignment material into the microcavities; irradiating polarizedlight to the photo-alignment material; baking the photo-alignmentmaterial; and injecting a liquid crystal material in the microcavities.12. The method of claim 11, wherein the photo-alignment materialincludes a photoisomer type material.
 13. The method of claim 12,wherein the photo-alignment material forms a cis type photoisomer uponirradiation of the polarized light.
 14. The method of claim 13, whereinthe photo-alignment material includes azo benzene.
 15. The method ofclaim 14, wherein the polarized light has a wavelength equal to or lessthan 365 nanometers.
 16. The method of claim 15, wherein the polarizedlight has energy of about 4 J to about 6 J.
 17. The method of claim 12,comprising: forming a lower insulating layer disposed between themicrocavities and the roof layer; forming an upper insulating layer onthe roof layer; and forming a capping layer on the upper insulatinglayer.
 18. The method of claim 17, wherein a liquid crystal injectionhole forming region is disposed between the microcavities, and thecapping layer is formed to cover the liquid crystal injection holeforming region.
 19. The method of claim 18, wherein an interlayerinsulating layer is disposed between the first electrode and the secondelectrode, the first electrode has a planar shape, and the secondelectrode includes a plurality of branch electrodes.
 20. The method ofclaim 19, wherein the branch electrodes overlap the first electrode ofthe planar shape.